Thermoplastic polymer compositions containing polycarbonate as a main component are known. In this connection, there are also known additives which decrease adhesion of thermoplastic polymers to metals. For such purposes, additives such as products of complete or partial esterification of monocarboxylic or dicarboxylic aliphatic acids having long carbon chain with monohydric or polyhydric alcohols or phenols are employed.
According to European Patent No. 122,759 polyesters having g a degree of polymerization from 3 to 12 are used as additives that decrease adhesion of polycarbonates to processing mold. Those polyesters are obtained from aliphatic dicarboxylic acids containing from 2 to 6 carbon atoms and pentaerythritol, partially esterified by aliphatic monocarboxylic acids containing 2 to 6 carbon atoms.
According to Japanese Patent Application No. 86/261349, esters of aliphatic monocarboxylic acids containing from 12 to 30 carbon atoms reacted with C.ltoreq.0 aliphatic alcohols or polyols are used as additives to decrease the adhesion of the polymer compositions to the processing mold.
Additives of this type are introduced by physical modification, applying 0.01 to 2.0 parts by weight of the additive per 100 parts by weight of high molecular weight of thermoplastic polymer, especially polycarbonate, which are mixed with dissolved, molten, or powdered polymer.
Processing molds, especially injections molds, are sometimes blocked during the processing of known thermoplastic polymer compositions. This makes the operation troublesome.
It is an aim of this invention to provide thermoplastic polymer compositions which exhibit decreased adhesion to metals and thus easily released from processing molds, thus avoiding blocking of the processing apparatus or devices.